Method and Apparatus for Aligning Laser to Optical System

ABSTRACT

An improved method and apparatus for aligning laser systems to optical systems at long distances. An embodiment of this uses a reflective material with markings which reflects light back along its angle of incidence to permit a user to align the two systems.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of PPA Ser. No. 61/841,615, filed2013 Jul. 1 by the present inventors, which is incorporated byreference.

BACKGROUND

1. Discussion of Prior Art

This application relates to aligning a physically separate laser to adirect-view optical system for use on distant targets

2. Prior Art

Modern lasers and laser rangefinders are used by long range shooters toilluminate a target and measure the distance to a target, respectively.These devices include several lasers, including a visible one that theshooter can use to align the laser rangefinder to an optical device thatis used to see the target. One challenge in using the visible laser toalign the device to the direct-view optical system is that the laser isdifficult to see in full daylight. The brightness of the sun overwhelmsthe eye's ability to see the laser, even with an optical system.Currently, users desiring to align their laser system to their opticalsystem have to perform the alignment at short distances or duringperiods of low ambient illumination (before dawn or after dusk) so thatthey can see the laser spot. These short distances are much less thanthe distances that some users shoot targets at, which could be over 1000meters. Aligning the systems at short distances introduces parallax intothe alignment, making it difficult for the user to properly lase a longdistance target. If misaligned, the laser rangefinder will suffer adecrease in performance, most likely returning the incorrect range totarget.

The alignment target in U.S. Pat. No. 6,815,838 to Daubenspeck on 2002Feb. 20 is appropriate for use with semiconductor devices, but not in anoutdoor setting or at long distances. The method described in U.S. Pat.No. 6,793,494 to Varshneya on 2002 May 20 details a means for aligning asmall arms transmitter, but fails to address how to see the laser atlong distances. The U.S. Pat. No. 5,410,815 to Parikh on 1994 Apr. 29describes a system to align a weapon mounted laser with the weapon'sboresight, but it is a complex optomechanical system, and unsuitable forfield work. It is also tailored specifically for a particular lasersystem in a training environment.

Forrest describes an apparatus for boresighting a firearm in U.S. Pat.No. 4,530,162 on 1983 Aug. 8 that shines a collimated light sourcethrough the barrel, which is acceptable for aligning a rifle scope, butprovides no means to align a laser to the scope. The U.S. Pat. No.5,001,836 to Cameron on 1990 Feb. 5 describes a means similar to U.S.Pat. No. 4,530,162, using a barrel-mounted laser to align a rifle scope,but does not address how to align a laser for long distances.

ADVANTAGES

One advantage of one or more aspects is to allow the user to more easilysee the laser spot in various ambient lighting conditions, especially atlonger distances. Another advantage is that alignment target may reducethe time it takes for a shooter to align the laser to a telescopicscope. Another advantage is that the target will allow the user to moreprecisely align the laser system to the optical system. Other advantagesinclude ease of use, low complexity, and low cost. These and otheradvantages will become apparent from a consideration of the ensuingdescription and accompanying drawings.

DRAWINGS—FIGURES

FIG. 1 shows various aspects of a target supplied with a reflectivematerial and support backing in accordance with one embodiment.

FIG. 2 shows example of weapon-mounted laser system emitting a laserthat is reflected by one embodiment of a target

FIG. 3 shows a flowchart of method for aligning weapon-mounted lasersystem with one embodiment of a target

FIG. 4 shows an illustration of the steps in FIG. 3

FIGS. 5A and 5B shows various aspects of a target supplied with flexiblematerials in accordance with another embodiment.

DRAWINGS—REFERENCE NUMERALS

Weapon-mounted laser system with adjustment mechanism 12 Weapon-mountedoptical system 14 Weapon 16 Light source 18 Reflective Target 20Reflected light 22 Telescopic Scope Markings 24 Reflective material 26Support structure 28 Retroreflector 30 Flexible reflective material 32Flexible support material 34 Flexible string 36 Weight 38 Targetmarkings 40

DETAILED DESCRIPTION—FIRST EMBODIMENT—FIG. 1

One embodiment of the target 20 is illustrated in FIG. 1. The target 20consists of a reflective material 26 attached to a support structure 28.The reflective material 26 may consist of a plurality of retroreflectors30 that reflect incoming light 18 back in the direction from which itentered the retro reflector 30.

In one embodiment, the reflective material 26 is an adhesive sheet, suchas 3M reflective sheeting for traffic signs, which is attached to asupport structure 28. The reflective material 26 can come in otherforms, such as transfer films, fabrics, pressure-sensitive adhesivefilms, etc. In one embodiment, the support structure 28 is aluminum;however, the support structure 28 can consist of any material thatprotects the reflective material 26 from normal wear, such as nylonfabric or plastic sheets.

OPERATION—FIRST EMBODIMENT—FIGS. 2-4

FIG. 2 shows the basic configuration of one embodiment. The method orarrangement of mounting the optical system 14 and laser system 12 uponthe weapon 16 will be well known to those with ordinary skill in themechanical and shooting arts. The method of adjusting the laser system's12 alignment will be well known to those with ordinary skill in theshooting arts.

FIG. 3 shows a flowchart of how to align the laser system 12 with theoptical system 14 using one embodiment of the target 20. The target 20is affixed at a short distance, with its reflective surface pointed backat the laser system. The laser system 12, mounted on the weapon 16 alongwith the optical system 14, is configured to emit its light 18. Theweapon 16, with attached laser system 12 and optical system 14 isscanned back and forth near the target until the reflected light 22 isvisible through the optical system 14 on the target 20. The offset fromthe optical system's markings 24 is noted, and the adjustment mechanismof the laser system 12 is used to move the reflected light 22 on thetarget 20 until the reflected light 22 is located in the center of theoptical system's 14 field of view. This results in a coarse alignment ofthe laser system and optical system.

The target 20 is then moved to the desired shooting range or maximumeffective range of the weapon and affixed there. The process ofactivating the light source 18, scanning the optical system 14 near thetarget 20, and adjusting the laser system 12 is repeated at this longerrange to refine the alignment between optical system 14 and laser system12.

FIG. 4 shows an illustration of what will be seen through the opticalsystem 14 while performing the process described in FIG. 3.

DESCRIPTION—ALTERNATIVE EMBODIMENT—FIGS. 5A and B

FIG. 5A shows an additional embodiment of target 20 that uses a fabricreflective material 26 and nylon fabric support structure 28. Thisembodiment includes a cross marking 40 on the reflective material 26 toassist with alignment, however, the marking could consist of differentshapes, such as a box, dot, circle, etc. This embodiment also includes aflexible string 36 attached to the support structure 28 so that thetarget 20 can be hung from various available structures. Additionally,this embodiment may include a weight 40 sewn into the support structure28 that helps prevent the target 20 from moving when used outdoors.

FIG. 5B shows how the embodiment can be rolled up around the weight 40so that the target 20 can be stowed in a bag, backpack, or pocket.

CONCLUSION, RAMIFICATIONS, AND SCOPE

Accordingly, the reader will see that at least one embodiment of thetarget provides a low cost, lightweight, reliable apparatus that can beused by persons of almost any skill level to align a laser system to anoptical system. From the description above, a number of advantages ofsome embodiments of our alignment apparatus and method become evident:

-   -   1. The use of reflective material will permit a user to see a        laser at much further distances, which increases the accuracy of        the alignment between a laser system and an optical system, as        well as decreasing the time required to align the two.    -   2. The use of reflective material will permit a user to align        the two systems outdoors during the day.    -   3. The use of flexible materials will permit a user to carry an        embodiment with him for alignment in the field.    -   4. The use of markings on the reflective material will permit a        user to easily see the target and align the optical system upon        it.

While our above description contains many specificities, these shouldnot be construed as limitations on the scope, but rather as anexemplification of several embodiments thereof. Many other variationsare possible:

-   -   The support structure 28 may be either flexible or rigid.    -   The support structure 28 may be eliminated if the target 20 is        to be affixed to a permanent structure.    -   The target 20 may be shaped in other forms, such as circular or        man-shaped.    -   The size of the target 20 may be changed, such as increasing its        size for alignment at long ranges, or made smaller for        portability    -   The reflective material 26 may be of different form, such as a        flexible fabric or an adhesive sheet.    -   The target 20 may have different mechanisms for hanging it at        range, such as magnets for attaching to a metal surface, or a        flexible wire, or rope for hanging on a nail.    -   The reflective material 26 and support structure 28 may be of a        different color.    -   The reflective material 26 may have markings on it that could        allow a user to align the system more quickly, such as a grid        pattern, a dot, or similar.    -   The target 20 may have weights in it to help stabilize it in        high winds.    -   The target 20 may have a mechanism for supporting a flexible        embodiment, causing it to pop out when deployed.    -   The reflective 30 may have a different design, such as spherical        or corner.    -   The target 20 could take the form of a single retroreflector,        such as a corner cube.

Thus, the scope of the embodiments should be determined by the appendedclaims and their legal equivalents, rather than by the examples given.

We claim:
 1. A method of aligning a laser system to an optical system comprising reflecting a laser off a target comprised of a reflective material, whereby said laser system can easily be aligned at long distances.
 2. The method of claim 1 wherein said laser system is mounted upon a weapon.
 3. The method of claim 1 wherein said laser system has a mechanism for adjusting the orientation of its lasers.
 4. The method of claim 1 wherein said optical system is mounted upon a weapon.
 5. The method of claim 4 wherein said optical system is a telescopic rifle scope.
 6. The method of claim 1 wherein said reflective material is attached to a support material.
 7. The method of claim 6 wherein said reflective material and said support material are comprised of fabric.
 8. The method of claim 1 wherein said reflective material includes a marking upon it to enhance visibility.
 9. The method of claim 8 wherein said marking is shaped like a cross.
 10. The method of claim 1 wherein said laser system is mounted upon said optical system.
 11. A target comprising a reflective material that reflects incoming light back along its incidence angle, a support material that said reflective material is attached to, and a marking that increases visibility, whereby said target will enable user to align a laser system to an optical system at long distance.
 12. The target in claim 11 wherein said reflective material and said support material are fabric.
 13. The target in claim 12 wherein said support material has a string and a weight attached.
 14. The target in claim 12 wherein said reflective material and said support material provide means for said target to be rolled up.
 15. The target in claim 11 wherein said support material is a rigid material.
 16. The target in claim 15 wherein said support material has a mounting hole.
 17. The target in claim 10 wherein said marking is in the shape of a cross. 